--- a/Sphinx/source/plugins/python.rst	Sat Jul 25 21:23:13 2020 +0200
+++ b/Sphinx/source/plugins/python.rst	Tue Aug 04 20:53:18 2020 +0200
@@ -567,6 +567,11 @@
 Performance and concurrency
 ---------------------------
 
+**Important:** This section only applies to UNIX-like systems. The
+``multiprocessing`` package will not work on Microsoft Windows as the
+latter OS has a different model for `forking processes
+<https://en.wikipedia.org/wiki/Fork_(system_call)>`__.
+
 .. highlight:: python
 
 Let us consider the following sample Python script that makes a